Hey there hoping to get input on this just couldn't wrap my head around the problem.

I have a 1992 type-r FD and i just recently did a FULL non seq mod using rotary Resurrection and the picture i attached as a hose diagram for reference.

When i started the car everything seemed fine and it idled perfect. It wasn't until 10 minutes after idling when i started hearing a 'whistling' noise coming somewhere around the throttle body area. As i rev the motor up the sound completely disappears.

The belts and all acc. are fine. But last year i took out the butterfly valves in the throttle body to clean them.

Could it be from a small amount of air squeezing through the butterfly valves causing this sound? I checked 3 times and couldn't find any open nipples that i havent plugged off and like i said it sounds like its idling perfectly fine.

Couldnt find anything on the internet other than belt problems and that i know on my end is perfectly fine! Any ideas would be awesome thanks guys!

 

how is the O ring,on the throttle body.. between the Throttle body and the Elbow?.

 

Looked good and didnt show any signs of fatigue